I wouldn't advise buying refills at just any supply house. Getting a refill that works properly in a Bosch blade will need Bosch refill. Even then Bosch makes refills for at least three different style blades.
You must have the right refill! The rubber part is supported by metal strips that do not come with the proper refill. Refills from any other manufacturer will use a rubber with plastic support integral to it. Once the metal is thrown away, only a complete blade will fix the mess. The complete blade is a special MB part made by Bosch. Using a generic Bosch blade also is not the answer.
Bosch Master, ASE Master, L1
33 years MB technician