DNSSEC keys deletion for domain failed

Hello together

when i try to delete the dnssec keys on my Domain tometzki.de i got the following error via mail:

Removing DNSSEC associated with the domain tometzki.de We're sorry to report that the operation failed after we forwarded your request to our registrar associate. This is because:

2400 : Command failed (549 Command failed; 53300102912 Nameserver error [ERROR: 901 Unexpected RCODE (target, entity, RCODE) (ns-1933.awsdns-49.co.uk./205.251.199.141:53, tometzki.de, REFUSED)]) Contact Amazon Web Services Customer Support, and we'll figure out what happened.

Could you help me ?

best regards Damian