Build quality leaves much to be desired

Have I bought this filter as protection for my lens and can first times a positive note that I can perceive no loss in image quality through the filter.
Unfortunately mitlerweile sitting (after about 2months) the filter disk only loosely, as amended. If you can easily put pressure when cleaning shifts the disc! This then she sits at a slight angle to the lens.
The filter is cheap but accordingly also speak not very stable, or I've caught a bad copy. The next time I want to get with me no more Hama!