One of the first things to do when configuring A2Billing is set the base currency. This will be the currency that your rate cards are in. If you create call rates and then change the base currency afterwards, the rates will get messed up.
The first step is to edit the base currency setting. This can be found under SYSTEM SETTINGS / global / base_currency –
It is very important that you change the 3 letter value to a valid currency code. If you are not sure what these are then check in step 2 first.
Step 2 is to run a currency update. This gets all of the current currency exchange rates from Yahoo and updates all of the currencies in A2Billing. This can be found in BILLING / Currency List –
The last thing to do is to check that you have the automated job set up that automatically updates the currency exchange rates every day. This should have been done as part of the a2billing install, and is done on all SysAdminMan VPS servers that have a2billing installed.
Running from cron there will be something like this –