Today, was rang is considered a non-standard form since the accepted past participle of ring is rung. In earlier centuries, however, this was not always the case:
June 5, was rang at the pariſh church of St. Leonard, Shoreditch, a compleat peal of caters, on Stedman's principle, being the ſecond production in that critical method. The peal conſiſted of 5184 changes, and was performed in three hours and 47 minutes, by the ſociety of Cumberland Youths. — The Sporting Magazine, June 1796, 162.
The lady rang the bell to enquire the cause of it, but no answer. The bell was rang again, but there was no answer. — Rev. G. Owen, Counsels to Domesticks, Baltimore, 1844, 47.
With the rapid expansion of compulsory education in the mid-19th century and the grammar books that accompanied it, rang as a participle, along with other now non-standard forms, was drilled out of American youth, as in this sentence a student was to correct:
I begun to study early, studied hard till the bell was rang, then I run all the way and come to school in season, and recited awl my lessons perfect. — Report of the annual examination of the public schools, Boston, 1852.
Before this standardization, there was a good bit of variation in strong verbs with the umlaut paradigm i, a, u. Thus Shakespeare:
… or I will scarce think you have swam in a gondola. — As You Like It, 4.1.
A number of these forms survived more readily in Scotland and the North:
But our humbler home is yet a while on the earth, and of the earth in humbler strain it is that we would speak—though had Heaven made us a poet, we had sang to Tellus many a lofty hymn. — Blackwood’s Edinburgh Magazine 37/234 (April 1835).
The love which had sprang up in his heart was not the sudden, changeable fancy of a boy, but rather the wild, fierce passion of a man of strong will and imperious temper. — Arthur Conan Doyle, A Study in Scarlet, n.d., orig. 1887, 130.
This is not to say that those countless people on Yelp or Trip Advisor who write was rang lie in an unbroken tradition with Shakespeare and Conan Doyle, but such forms rarely appear out of nowhere and often continue a shadow existence in spoken dialect. It’s still English, just no longer considered standard because educated elites preferred other forms.