I have a T Mobile Comapct V which is at times

I have a T Mobile Comapct V which is at times having long delays with receiving text messages and sometimes not receiving at all. The phone will light up and then the text not always coming through. I have had the network reset by t mobile and all the settings sent to me. I have also had the handset replaced and all was ok for abot 3 - 4 weeks but I am now having the same problem again..... its ver frustrating