Bad Reception all of a sudden, incl. dropped calls

The incident happened about 1 month ago, when all of a sudden my phone had no network coverage. It lasted for almost two days, when I thought this was odd. I then called MTN call centres and then they directed me to Network coverage department, after talking to them, they said they do not do this type of work, it could be a problem with the handset. I tested 2 sim cards on the same device, and it worked fine. Another MTN number was also working with full coverage on my handset. I then called network coverage again and mentioned that the problem has to be on their side. they eventually asked an Engineer to do something and then I had network coverage. Although the problem was resolved, the maximum coverage I get is 2 bars (out of 5) always. It has been almost a month since this incident, but I am having problems with cross calling(I dial a number and then someone else answers, not the number I called) and also numerous dropped calls daily.<br> I have since called the customer call centre, MTN network coverage and each one says call the other.<br> <br> If someone from MTN who knows what to do, please help with this issue.