Bathtub replacement or improvement

[Daniel Suarez]

I have a working condition tub that seems to be peeling (view photo) I want to avoid replacing it because it seems to be stucked to the wall so the removing part will be very hard and I was wondering if anyone had experience improving the looks of it or if there's a workaround. We tried paitning it but the peeling apeared again after a week or so. 

Thanks in advance.