i have a unlocked verizon blackberry tour with EDGE issue

hi i'm new... i just recently purchase a unlocked verizon blackberry tour 9630 from amazon.com and i bought a DIGICEL sim card with data plan included... but the phone having problems keeping higher case EDGE the guys at DIGICEL said it something with verizon or in the phone it self.. so what is the best solution can i get to solve with lower case "edge" to higher case "EDGE" its keep off and on....i need help badly

thanks

Have you placed the unit in 2G/gsm in manage connections ??

Have you inputted digicel's apn settings in options-advanced-tcp ??