Help Huawei Ascend Y530 dialling error

[Spike176]

I own an Ascend Y530. Today, I was half-way through dialling a friend's number (A) when an incoming call (B) over-rode the attempted outgoing call. Since then, whenever I try to dial my friend's phone number (A), the phone number of (B) over-rides it and the call goes to (B) instead of (A). Any ideas?