Service problem. Showing an "x"

Hey guys.

I have an un-rooted T-mobile (Phoenix AZ) Mytouch 4g that seems to be having service problems. Roughly once-a-day my service will go from full bars to zero connection. The connection icon will display an "x".

I found that I can get connection back by calling a phone number repeatedly. The call will usually not connect for the first 10 times, then after that, I will usually get full service back.

I've also tried re-booting the phone during the service outage, and that has not solved the problem.

If anyone can help me solve this problem, I will be much grateful. I've search this forum for any threads of anyone with the same problem, and could not seem to find any answers. I'm sorry if this problem has already been discussed.

Thanks again,
Bennichs