Crossed lines on mobile when phoning UK

[MikeK]

A strange one, I have been ringing a mobile in the UK which has worked fine up until a week ago. Now an "international ring" is heard when trying to connect. The phone has been answered by a variety of different people upon connecting, I can hear them but they cannot hear me. I am on a Turkcell contract, anyone else had a similar experience, any suggestions what to try to resolve this?. Many thanks.

[Hector]

Has the UK mobile been stolen by any chance?

[MikeK]

No, not stolen, other family members ring it often in the UK and get through no problem. It's a different person answering each time with different accents, it seems as if it's connecting to some random number each time we try it. Very strange.