Best bank for savings.

My wife puts RD$5000 into Banco Popular every month, savings for her old age. They have, to me a ridiculous system whereby every month they close the account then open a new account into which the balance from A/C no1 is paid plus the next new RD$5000. The document states that 2.5% interest will be paid at the end of a year but then go on to say that the money can be withdrawn after 1 month!! This also means that any one month's account never exists for a year. Every month this palaver takes over half an hour. There must be a better way of investing monthly savings on a cumulative basis. Any suggestions ? As for her current balance, now into 6 figures, is there any place she can invest it at a better rate than 2.5% even if locked up for a number of years? She originally opened the account with RD$5000 at something like 13% but they then told her she could not add to it and that in any case the interest rate had gone down. We have only just realised that we cannot remember her ever being credited with any interest and that's a period of over 2 years. At that time she had little or no idea about savings account and my spanish must have been so bad that I understood nowhere near enough. Any helpful suggestions would be very welcome.