VerizonWireless charged what was already paid for Atlanta, Georgia

Have 5 lines in account. From January 2011 pay for limited (250 messages) texting $5 each for 2 lines and limited (5000 messages) texting $20 for the 3rd line, in total = $5*2+$20 = $30. Blocked texting for the other 2 lines to avoid extra texting charges. After 6 months learn that for the same $30 we could have unlimited texting for the whole account, all lines.
Nobody in Verizon told me that it was possible until I get extra $419 for over the limit texting. In the same month I am overseas for 20 days and get $374.5 roaming charges. Total monthly charge becomes $1040.18. Is not is too excessive? Spoke to csr and got $209.5 credit, but the remaining $209.5 refused to remove even after speaking to supervisor. Being trapped by 2 years contract cannot get out.