I would go the chap you bought it from - gtet your £ back, or try consumer advice .
Last resort find a specialist auto transmission place near to you and ask thier advice.
Q
AUTOMATIC TRANSMISSION SPECIALISTS: Could you recommend any automatic gearbox specialists prepared to service and rebuild automatic boxes rather than simply replace them?
A
• King Automatics, The Chalk Pit, College Road, Epsom, Surrey, tel: 01372 728769.
• Automatic Transmissions (Tattersall), Tattersall Bridge, near Coningsby, Lincoln, tel: 01526 342956.
• JP (Automatic Transmissions) Ltd,
www.jpat.co.uk, Units 4a & 4b Pear Tree Ind Est, Upper Langford, N Somerset, BS40 5DJ, tel: 01934 852772.
• Sussex Automatics,www.sussexautos.co.uk
• FEDERATION OF AUTOMATIC TRANSMISSION ENGINEERS,www.fedauto.co.uk