The frequent delays or even failures when requesting tariff changes by SMS is really annoying and a shame as well. May be I should add a warning that SMS-triggered tariff changes sometimes are not applied at all at
LIDL mobile - Prepaid Wireless Internet Access which currently says: "tariff changes made online seem to become effective faster"
P.S.: just changed the text to "Tariff changes requested by SMS often take much longer to take effect or even fail sometimes, while those made online seem to become effective reliably and much faster. Therefore tariff changes should preferable be made online."