Feedback on N2P camera

I've had 2 N2P cameras for 4 years. About 20 % of the 3 minute recorded files are unplayable - I geta an error that states they cannot play. Other than that the remaining files playback fine, pictures are clear and bright. I have contacted customer service multiple times - they are always very responsive but have offered not solution. I have upgraded and replaced the sim cards multiple times but this does not solve the problem. A 20 % failure rate is unacceptable, but that's the best I can expect. I'm surprised no one else has posted a similar experience. It can't be just me.