Yes, here you can switch between tariffs at anytime, though tariff changes will not take effect before the end of the ongoing billing period (which is one day for the Classic tariff and 30 days for the Smart tariffs).

How long does it take to get the bonus 5 eur???
p.

Usually within 1-2 weeks.

If you choose the Lidl Community-Flat until the 29. September 2013 you'll get this pack for 12 months free of charge! This offer is available for new and existing customers.