If its redirecting entirely to the banks systems then there's not much you can do, unless your bank allows you to customize the payment gateway somehow. If not, about the only thing I could think of is attempting to "integrate" it by placing it in an iframe and keeping your website layout, but that just looks even more unprofessional IMO and will not rid the iframe of the banks logo (you will still see the same things as before).
IroncladServers.ca - Shared.Reseller.VPS.Dedi.Colo
Solid Canadian & US network, 24.7.365 support, 100% owned & maintained
Probably we would need to contact the bank to see if they are willing to customize the payment page.
Few banks payment systems(especially for online payments) usually works most likely using this logic,
1. Our website would redirect the online user to the corresponding banks page. Some values needs to parsed like the required amount etc.,
2. After the payment is successful, the banks server would send a positive response to our website server, and a thanks page is displayed from our website.
3. If there is a negative response from the bank server, then we would need to display corresponding page to the user.
Generally Iframe wouldn't be an idle solution as stated by ironclad, however please check with the bank's technical department and they should be able to offer their official documentation on how to integrate their payment system. There may be a cost associated and that depends on the bank.