i think u should go with Qtel they are offering iPhone 4 32 GB only for 3350 and also replacing your sim is also free from Qtel. with Vodafone u also get sim free but thier price is slight high and u have to go for a face time and i think no one needs it now a days as thier network sucks. with Qtel u will get call rates high but network is world class also Qtel have better internet packs for postpaid if u use qtel internet packs u will get high internet speed upto 5-6mbps....Qtel is better. and sorry have no idea about iphone 4 problems
gud luck