It's a commonly used way to refer to Radio Shack. Usually derisive in nature, and used by people with a high familiarity of either electronic components or audio equipment.
The term is an extension of its former expression 'Bollocking' Used to thoroughly inform and highlight a person’s ill behaviour, raising awareness in order to prevent the action from occurring again in the future.
When paired ‘Ramshack’ indicates the issues raised are far beyond repair, alternatively it may refer to complete insolence in ones errors.