Airtel — change in broadband plan

Address:

600119

I requested for change in broadband plan.My current plan is 799, from tis i lik to change for 999 plan. I paid extra amount rs.2000 for six months on Dec 8. But my plan didnt change. I tried to cal and mail regarding this, but my request is not solved. its been more than 15 days, but still no progress. I have mailed regarding this, and got a reply, that issue will resolve in 72hrs. But nothing happened. Likewise i mailed 4 times.When will my issue b resolved?