UC Advance (New Claim)

So this is a help post and to to understand some things.

Why is it that some advances are rejected and then some are approved? Is it down to the advisers looking at them?

Basically I requested one and then it was rejected - I thought maybe because it was too high? And then I've requested again, it was approved - so I tried again and got more.

Stupidly I've been getting new claim advances every 7 months because of no payment and then make a new claim.

Why is there no system in place to stop this?

What are my options? I've had my latest one closed due to duplicate claim apparently?

I hold my hands up - I have several debts, gambling problems, and mental health, along with autism.

I have thought about my options and I want to pay it all back. Who do I contact UC or DWP Debt?

I have got myself into a mess and want to get help.