Roofing PROBLEM

My grandmother decided to get the roof at her house done. Mind you the roof is a flat roof. Anywho the roof has on and off leaks so she decided to pay a company 3,000$ to get it fixed. (She asked how much the insurance would pay and they wouldnt pay much at all to get it fixed GRRR) I had no idea when the repair was going on otherwise I would have told her NOT to pay them the full amount until she is sure the job was done right. TOO LATE she paid them the full amount after the down payment without having someone check the work. Anyway come to find out they only fixed the leaking area and nothing else. Did a cheap quick fix. She does not have enough money to sue them and apparently her daughters have tried to call these people and have not gotten a response or a call back. What should/can I do? I mean we are not talking 100$, its 3,000$ and I dont think this is right AT ALL! Any suggestions? I have yet to call and plan on doing so ASAP just needed input or suggestions before I do so.