Cant recieve call from certain numbers especially from my work

[shaqmans]

Hi,

I have been experiencing a lot of problems with my Z1. I can recieve calls from a lot of other numbers but not my work numbers which is a bit confusing. We have different departments but up to 3 different departments can't call me as its always showing busy signal. I called Vodaphone customer service and they did checks and said its not coming from there side and as far as they know everything is ok. I was advised to contact my manufacturer which is Sony.  

Can someone please help me to solve this as its affecting my work?

Thanks.

[SergioPL1]

It is possible that you have certain 3rd party application installed on the phone. Try in safe mode:

/t5/FAQ/How-to-boot-your-phone-into-safe-mode/td-p/348008

Also, just to make sure everything is fine, try your SIM card in another phone.

You can also try other SIM card in your phone and see if that happens too.