Be careful when purchasing a yoga club membership or any service on an instalment plan because if the vendor goes bankrupt, you could lose both your purchase and your money - and it's perfectly legal. That's the message being put out by the Consumer Council after a doubling in complaints from customers whose accounts continue to be drained by credit card instalment plans after a company closes. Here's what many customers don't know. When they buy a product or service through credit card instalments, the credit provider pays the sum in full to the vendor immediately. The instalments the customer pays after that do not go to the vendor but to the credit provider. Any business between the customer and vendor is finished and whatever happens to the vendor - including bankruptcy - does not affect the customer's obligation to repay the credit provider. 'In most cases, instalment payment plans are effectively loan agreements between the bank and the customer,' a spokeswoman from the Hong Kong Monetary Authority said. Credit companies observe a global agreement that they should repay consumers if they cannot get the product or service they paid for - but that only applies to transactions paid in full, not with instalments. The two methods of payment are two different mechanisms, according to the council's chief executive, Connie Lau Yin-hing. Most credit card instalment contracts spelled out the customer's obligation to keep paying even if the service provider closed down, but banks should make such information explicit, Lau said. The Monetary Authority is in talks with the banking industry on what should be done to prevent customers from misunderstanding the terms of loan agreements, which vary across banks. It aims to issue guidelines to banks within two months. Fifty-four complaints were made in the first half of the year, compared to 23 in the same period last year. Those complaints involve a total of HK$610,000 paid for products or services that have not been provided. Causeway Bay-based fitness club Yoga Yoga International closed down at the end of March, with more than 60 members reporting to police that their prepayments were not refunded. Planet Yoga, a chain with three outlets and 13,000 members, closed in May.