HP Instant Ink complaint: Instant ink software incurred me cost even when I cancelled my account

On Fri10 July I canceled my Instant ink account. After that, I inserted regular cartridges and the message came on printer display The indicated cartridges are not intended for use in the printer. I called HP instant ink support to resolve the issue. I accidentally mixed the cartridges and inserted back the inserted cartridges backs in the error message went away, I printed a couple more documents for testing purpose thinking the printer is working on non-instant ink cartridges. I printed another 100 pages on Saturday 11 July. Out of interest, I checked my Instant ink account to see if the account has been cancelled and to my surprise, I noticed I have incurred a £12 and odd pence charge.
Ideally, if the software is intelligent enough to reorder ink from HP when it sends information over the internet about ink levels then it should also be smart enough to detect a cancelled account and make the instant-ink cartridges invalid to use. This has left a bad taste in my mouth about HP instant ink cartridges