The instore receipts had the vouchers for the points.

I think jchand means that the TOTAL Clubcard points shown on the bottom cannot cope with more than 100,000 balance. It is still possible - perhaps for anti-fraud reasons - that tills cannot cope with more than 1000 points in one transactions, although this seems unlikely since many of us bought multiple bottles of champagne last year in one go for well over 1000 bonus points!