Additionally, I have a LOT of experience with this from when I worked for a health insurance carrier. It may have been cancelled EFFECTIVE 10 weeks ago but it's about 100% certain that the cancellation was made retroactively. Insurance carriers would MUCH prefer not to make cancellations for non-payment and will only do so after there have been several notices. However, when they do cancel, it'll be retroactive to the last date paid; if the last day for which they received payment was June 30, they'll make the cancellation effective July 1, even if they don't do it till September.
So it's not so much that he was taking premiums after the policy was already cancelled, but that he took premiums for a period during which the policy was in force but has SINCE been cancelled.
He must either pay the insurance carrier to have it reinstated, find new coverage, or return the monies taken for the premiums to you.