TROUBLESHOOTING MICROMAX Q5 mobile-network connectivity signal problem

I HAVE RECENTLY PURCHASED A NEW MICROMAX Q5 HANDSET.AFTER USING IT FOR FEW DAYS I NOTICED A PROBLEM WITH THE GADGET,IT IS A DUAL SIM MOBILE,BUT ITS NETWORK DOES NOT WORKS PROPERLY AT ALL,EVEN IF THE TOWER DISPLAYING IN THE HANDSET IS FULL.IN THE MEANTIME I TRIED IT BY WITHOUT USING THE TWO GSM SIM SIMULTANOESLY,BUT THE SAME PROBLEM IS STILL THERE.LITERALY I HARDLY GET ANY CONNECTION....EVEN IF IAM USING THE BEST MOBILE SERVICE PROVIDER...COULD YOU PLEASE HELP ME?