Dude
Probably, failing , needs servicing
Forget all that , this panel is known to lose its memory and lose the plot so it has failed and is faulty
As Pete said it's the panel not really the keypad
If your keys worked try keeping hold of the keypad it will sell on eBay for some change or more
£500 is probably the cheaper end of the market but that's still with some kind of contract
£650 with a WiFi connection might be better to do , so pay a little more and get it over and done with