To expect a toilet seat to last longer than a year

[TheRugbyValkyrie]

The latest set a new record of six weeks before one of the hinges snapped!
I have no idea what I'm doing wrong but I can't seem to find a toilet seat that lasts longer than a year.
Having three boys I'm pretty strict with cleaning and generally give a wipe over at the end of the day but every single one rots at the hinges.
Any tips on where I can find an invincible toilet seat?
Does anyone else have this problem?

What do you use to clean it? My MiL is an avid bathroom cleaner - with the result that she wrecked her brand new bathroom suite in 6 months.

Do you buy the ones with plastic or metal hinges?

I use Mr Sainsbury's own brand cleaner and despite looking for seats with plastic hinges, I've never found one. Where can I find this Holy Grail of toilet seats?

We've only ever had set with plastic hinges - which can be easily replaced with a kit like this.
www.diy.com/departments/euroflo-white-plastic-toilet-seat-hinge/334060_BQ.prd

I think Wickes do all plastic www.wickes.co.uk/Wickes-White-Thermoplastic-Soft-Close-Toilet-Seat/p/149119

And at £8.99, this is an amazing plastic bargain www.screwfix.com/p/swirl-thermoplastic-standard-toilet-seat-polypropylene-white/1247g

www.screwfix.com/p/celmac-ruby-standard-toilet-seat-polypropylene/8081d

How heavy is the heaviest person using the toilet OP? I've done in a few toilets but I need to shed more than a few pounds.