you can shift to new pack. If your sun A/C enough amount, go to sun web and choose your Packand click to pay. If A/c have enough amount, then you will be shifted to new pack. That is all. Through sun mobile App Canot do it. I dont know why?? I tried but failed. Then turn to website.Will there be any disruption for existing customers? my plan is due for renewal on this month end. I would like to wait for 10 more days for things to normalize.