my ipad mini 4 has it's lcd display ruined

I wouldn't get it repaired. According to the specs, it has a fully laminated display, those are generally expensive to replace, it's like half of the price of a new iPad. The iPad mini 4 is from 2015, so it's supported as of now, but it has older hardware, such as the A8 processor, versus today's more efficient A12-A13 processors. The battery is also probably somewhat degraded.

In lieu of an actual iPad repair, Apple does in/out of warranty iPad replacements.

An out of warranty repair/device replacement is typically 60% of the iPad's original Apple OEM price.

You will just get another identical iPad Mini 4 model for that cost.

The iPad Mini 4 is nearly 5-years old, now!

Not really worth it after 5 years.

Better just to invest in an up to date, modern spec'd iPad that will be supported for another 5-7 years.

Sorry & Best of Luck to You!