Our Mystery Caller has been having problems topping up and hes looking for a sympathetic ear from the network call centres. He also wants to know how much hes paying for his calls and texts and whether theres a simple way of finding out how much credit he????

Our Mystery Caller doesnt know his GPRS from his elbow. Thats not going to stop him though. Its time to make his old phone play a new tune. And he knows just the one he wants. Just to complicate matters, the phone in question was never PAYT standard issu????r???r???r????

For this issue, at least, our Mystery Caller turns squaddie. Leaving aside the fact hes heard that mobile phones are more reliable than the militarys own radio net, he want to know the best way to keep in touch on his PAYT phone whilst hes away. What text????r???r???r????

Once upon a long time ago, our Mystery Caller had a rogue Nokia. Very occasionally, on a whim, it would cease to be a high tech communication device and turn instead into a lifeless piece of plastic. This was preceded failing to register a signal even tho????r???r???r????

Our mystery shopper is text mad, so he wants a tariff that offers lots of them, plus a phone with lots of memory to store them all. Will Southampton come up with the goods?

Our mystery shopper likes sending MMS across the border. Which of Irelands networks provides the best connectivity  and which phone the best picture quality?

Our mystery shopper is ready for a career in surveying and wants a device offering email and PowerPoint on the move  but he doesnt want to spend too much

Our Mystery Shopper hit the streets of Nottingham to find a handset for his mum in time for Mothers Day  something quick and easy to use on a very cheap talk plan

High street stores can verify a customers identity by asking for physical proof of their name and address, but what about web-based retailers?Steve Gold looks at how online dealers can protect themselves