Well an important aspect to that 'Solved' thread is you never did really fix the actual problem, syncing your Contacts. Instead you opted to use a workaround solution, exporting and importing your contacts list to a file.
If you were to take the time to get syncing working properly, it would just run automatically in the background so you wouldn't need to interact with it, and as part of the process you have you contacts also automatically backed up into your online Google account with a current listing on your phone with the same listing within your main, online Google account. On the other hand, exporting/importing a file, even while being relatively simple to do, is still a manual task, and involves you keeping track and maintaining your own backup files (i.e. if you start to inadvertently start storing different backups into different locations you'll later have an issue of some being out-of-date and possibly inaccurate while some are current.)
I'd suggest it's better to get the syncing problem fixed, and it might be prudent to just start over from scratch. It's more of a daunting project to get everything straightened out but once you put in the effort up front there's a long-term benefit where you don't need to mess with it.
Since you apparently have some contact entries only on your phone, some entries only in your online Google account, and a mix of entries that are in both places, this is going to get messy but it is important to get all your contact entries in one, primary location so you've got a master that contains all of your contacts.
-- Go into your phone's Settings >> Accounts menu and disable syncing for Contacts. You need to temporarily be sure this isn't running because you need to clean up your mix of duplicates and missing data contact entries.
-- With syncing disabled, start up the Contacts app on your phone and export your phone's contacts to a vcf file. Then copy it to computer or create an email message to yourself with that vcf file as an attachment.
-- On your computer, using a web browser, go to
https://contacts.google.com
and that will open up your Google account's Contacts list. You're probably find it easier to clean everything up using a larger screen with a keyboard and a mouse than the smaller screen on a phone with just the touch interface.
-- Now you want to import that vcf file you just created into your online Contacts. This merges the two, current databases and yes it's going to be messy mix of originals and duplicates. This is going to involve some time and effort as you sort through all the contact entries to get this cleared up. You want to get single entries for each person or business, with the correct and current numbers, addresses, etc. Don't rush the process and if it drags out for a few days as you confirm or verify questionable items, that's part of what needs to be done.
-- When you do finish up this project, you should have a nice, up-to-date, clean database of all your contacts. Depending on your level of paranoia you might want to backup your Contacts. There's an Export link in the left panel if you want to save it as a file.
-- Now that your Google account Contacts list is cleaned and intact it time to focus on your phone. Syncing for Contacts should still be disabled. Go into your Settings >> Apps menu, find and open the Contacts app entry, tap on Force stop, then find and top on Clear data. Using Clear data wipes the app's settings and config files, and wipes the app's Cache. This returns the Contacts app back to its original, first time used state. Something was messing up the syncing process before so now you'll be setting up the syncing up again but from a clean start. Start up the Contacts app and there shouldn't be any entries. Now go into the Settings >> Accounts menu and Enable syncing for Contacts. It'll will most likely take a few minutes for the syncing process to start and to download your Google account data so check on it later and hopefully you have a Contacts list that's identical on both your phone and if you use Google's web interface.
-- You might want to delete that vcf file you exported from the Contacts app previously. At this point it's old and not complete.