child support balance due

I am trying to find out balance on my child support in Texas I used to be able to see it on attorney general child support webpage until the mother changed it from a full service case now it shows payments only I contacted them and was told they don't have balance info because it is not a full service case even though a year ago i could see principal interest and total they told me to call collin count5 court and they cant tell me anything either I know i am down to interest only by calculating from last time i could see balance attorney genreal says they only have a order to deduct who would know this info how can i make sure they stop when i have paid all they said hire a lawyer why should i have to do that? the one i checked with want 3.00 0 non refundable retainer and 200 to 300 an hour