I used to have an account with HSBC, a Hong Kong Dollar account. I didn't use it often, eventually it stayed quiet for a few years. When I checked back, I found the money was gone.
There was about HK$600+, and it was all gone.
I went to a branch and ask them. They said because I didn't have transaction for a period of time, they started to charge a special fee monthly. It didn't take long to drain that HK$600 out of my account.
And this policy is clearly written in the long long HSBC terms and conditions... (Hey, did any of you read the text of that kind of thing?)
I wrote emails to their managers and customer relations, trying to get that HK$600 back. But they refused to do it.
That's my experience with HSBC.