The head of telecommunications provider Vodafone Germany, Philipp Rogge, has announced plans to leave the company at the end of the month in a surprise move after less than two years at the helm. Rogge, a 54-year-old Belgian, will be replaced after March 31 by Marcel de Groot, a current Vodafone Germany board member responsible for private customers, the company announced on Friday. “We will continue to do our homework” and “switch to attack,” said de Groot after his announcement as Vodafone Germany’s next chief executive. Rogge, the son of the late former International Olympic Committee presi…