DSL Umzug (relocation to a new address)

in April I have relocated to a new apartment within Frankfurt so I made a Umzug of my DSL and in the bill for June I have been charged additional 16.80 Euro plus taxes as Servicegebühr für Umzug, plus Versandkosten of 9.99. Can somebody help me understand what are these two additional charges for? P.s. for the umzug I received a new router and I sent my old back with the prepaid stamp that they sent me with the new router.