Gutters not put up level.

I Had gutters put in by Gutternuts. Firstly they required 100% payment up front due to it being under R10000. This is did. The service of putting them up went smoothly and it looked good. Once the first rain came then it was evident that they had made a mistake and not put the gutters level. The water was pouring out from a corner . I called them to come and fix it as i thought it was a leak. This is when they informed me that my 'roof' was not level. REALLY. So why did they not inform me when they put them up. Now I sit with ***** gutters due to them not using a spirit level and they are saying it is my problem. Be very careful using Gutternuts. Looks like I will need to get another competent company in to fix there mess.