Despite this being a necro, I think it bears saying, especially after my recent oddly coincedental run in with Bosch about this very thing; my pad had worn off after less than 8 months of sporadic use on a PEX220A; a £50 sander - I don't use my ROS as much as I thought I would - anyway Bosch in particular have a 3 yr warranty and after a couple of emails to Bosch UK that got ingnored - I did some less than flattering posts on thier FB page, also mentioning they had ignored my direct emails. This garnered a FB reply that they "took thier reputation and quality control very seriously", along with a reply to my emails (funny that) and an offer for replacements to be sent immediately without cost.
if your pad of whatever brand wears off too quick, I'd first try the manufacturers before shelling out on either a new base pad or just the velcro.