So you used a tire that is only supposed to last for 50 miles and shouldn't exceed 50mph or it will blow out.
You exceeded the speed.
In the week that the tire was on the car did you exceed the 50 miles of driving too?
You were lucky, that could have been a Darwin Award for yourself, or worse your negligent driving could have killed someone else.
Still maybe you will learn from your expensive mistake.
BTW you have written enough for your insurance company to invalidate your cover
