[atlas] Spurious "would violate your maximum daily spending limit"

I receive a:

 {"error":{"detail":"There was a
 problem with your request","status":400,"title":"Bad
 Request","code":102,"errors":[{"source":{"pointer":""},"detail":"Executing
 this measurement request would violate your maximum daily spending
 limit of 1000000.0 credits. Please stop some of your currently
 running measurements and try again."}

from the API.

The request is:

{'is_oneoff': True, 'definitions': [{'description': 'DNS resolution of
use-application-dns.net./A from AS #3215', 'af': 4, 'type': 'dns',
'query_argument': 'use-application-dns.net.', 'query_class': 'IN',
'query_type': 'A', 'set_rd_bit': True, 'protocol': 'UDP',
'use_probe_resolver': True}], 'probes': [{'requested': 100, 'type':
'asn', 'value': '3215', 'tags': {'include': ['system-ipv4-works',
'system-resolves-a-correctly', 'system-resolves

Which is very small. I run this sort of requests frequently. My daily
expenditure is small (13,680 credits). Why is it rejected?