My unlocked uk mobile which is registered to turkcell with sim has been refusing to connect me to turkish landline numbers, it says "prepaid customers cannot call this number" every time I try to ring a landline. It is fine on mobiles and I am not a prepaid customer. I took it to turkcell shop and they checked the sim and said no problem with card it must be phone. This has worked fine for a few years now so can i put the sim into the older uk mobile that was registered to turkcell previously. Thanks, would be interested to find out if anybody else has had this problem.